Revised Patch for JDBC timestamp problems - Mailing list pgsql-interfaces

Attached is a revised patch that removes the static SimpleDateFormat
objects that Thomas pointed out might be a problem.

thanks,
--Barry

PS.  Is this the correct way to submit patches by sending to
pgsql-patches?  It appeared from some of the comments on my last
submission that there is some other approval/review process that I
should go through first, but I don't see that documented anywhere, so if
I am doing something wrong, please forgive me, and point me in the right
direction.


PPS.  I have included and updated the comments from the original patch
request to reflect the changes made in this revised patch.

> Attached is a set of patches for a couple of bugs dealing with
> timestamps in JDBC.
>
> Bug#1) Incorrect timestamp stored in DB if client timezone different
> than DB.
>
> The buggy implementation of setTimestamp() in PreparedStatement simply
> used the toString() method of the java.sql.Timestamp object to convert
> to a string to send to the database.  The format of this is yyyy-MM-dd
> hh:mm:ss.SSS which doesn't include any timezone information.  Therefore
> the DB assumes its timezone since none is specified.  That is OK if the
> timezone of the client and server are the same, however if they are
> different the wrong timestamp is received by the server.  For example if
> the client is running in timezone GMT and wants to send the timestamp
> for noon to a server running in PST (GMT-8 hours), then the server will
> receive 2000-01-12 12:00:00.0 and interprete it as 2000-01-12
> 12:00:00-08 which is 2000-01-12 04:00:00 in GMT.  The fix is to send a
> format to the server that includes the timezone offset.  For simplicity
> sake the fix uses a SimpleDateFormat object with its timezone set to GMT
> so that '+00' can be used as the timezone for postgresql.  This is done
> as SimpleDateFormat doesn't support formating timezones in the way
> postgresql expects.
>
> Bug#2) Incorrect handling of partial seconds in getting timestamps from
> the DB
>
> When the SimpleDateFormat object parses a string with a format like
> yyyy-MM-dd hh:mm:ss.SS it expects the fractional seconds to be three
> decimal places (time precision in java is miliseconds = three decimal
> places).  This seems like a bug in java to me, but it is unlikely to be
> fixed anytime soon, so the postgresql code needed modification to
> support the java behaviour.  So for example a string of '2000-01-12
> 12:00:00.12-08' coming from the database was being converted to a
> timestamp object with a value of 2000-01-12 12:00:00.012GMT-08:00.  The
> fix was to check for a '.' in the string and if one is found append on
> an extra zero to the fractional seconds part.
>
>
> I also did some cleanup in ResultSet.getTimestamp().  This method has
> had multiple patches applied some of which resulted in code that was no
> longer needed.  For example the ISO timestamp format that postgresql
> uses specifies the timezone as an offset like '-08'.  Code was added at
> one point to convert the postgresql format to the java one which is
> GMT-08:00, however the old code was left around which did nothing.  So
> there was code that looked for yyyy-MM-dd hh:mm:sszzzzzzzzz and
> yyyy-MM-dd hh:mm:sszzz.  This second format would never be encountered
> because zzz (i.e. -08) would be converted into the former (also note
> that the SimpleDateFormat object treats zzzzzzzzz and zzz the same, the
> number of z's does not matter).
>
>
> There was another problem/fix mentioned on the email lists today by
> mcannon@internet.com which is also fixed by this patch:
>
> Bug#3) Fractional seconds lost when getting timestamp from the DB
> A patch by Jan Thomea handled the case of yyyy-MM-dd hh:mm:sszzzzzzzzz
> but not the fractional seconds version yyyy-MM-dd hh:mm:ss.SSzzzzzzzzz.
> The code is fixed to handle this case as well.*** interfaces/jdbc/org/postgresql/jdbc1/PreparedStatement.java.orig
FriJan 12 17:17:48 2001 
--- interfaces/jdbc/org/postgresql/jdbc1/PreparedStatement.java    Sat Jan 13 15:32:09 2001
***************
*** 312,321 ****
       */
      public void setDate(int parameterIndex, java.sql.Date x) throws SQLException
      {
!       SimpleDateFormat df = new SimpleDateFormat("''yyyy-MM-dd''");
!
        set(parameterIndex, df.format(x));
!
        // The above is how the date should be handled.
        //
        // However, in JDK's prior to 1.1.6 (confirmed with the
--- 312,320 ----
       */
      public void setDate(int parameterIndex, java.sql.Date x) throws SQLException
      {
!           SimpleDateFormat df = new SimpleDateFormat("''yyyy-MM-dd''");
        set(parameterIndex, df.format(x));
!
        // The above is how the date should be handled.
        //
        // However, in JDK's prior to 1.1.6 (confirmed with the
***************
*** 350,357 ****
       * @exception SQLException if a database access error occurs
       */
      public void setTimestamp(int parameterIndex, Timestamp x) throws SQLException
!     {
!         set(parameterIndex, "'" + x.toString() + "'");
      }

      /**
--- 349,360 ----
       * @exception SQLException if a database access error occurs
       */
      public void setTimestamp(int parameterIndex, Timestamp x) throws SQLException
!         {
!           SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
!           df.setTimeZone(TimeZone.getTimeZone("GMT"));
!           StringBuffer strBuf = new StringBuffer("'");
!           strBuf.append(df.format(x)).append('.').append(x.getNanos()/10000000).append("+00'");
!       set(parameterIndex, strBuf.toString());
      }

      /**
*** interfaces/jdbc/org/postgresql/jdbc1/ResultSet.java.orig    Fri Jan 12 17:18:45 2001
--- interfaces/jdbc/org/postgresql/jdbc1/ResultSet.java    Sat Jan 13 15:25:37 2001
***************
*** 462,486 ****
      String s = getString(columnIndex);
      if(s==null)
      return null;
!
!     // This works, but it's commented out because Michael Stephenson's
!     // solution is better still:
!     //SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
!
!     // Michael Stephenson's solution:
      SimpleDateFormat df = null;
!     if (s.length()>21 && s.indexOf('.') != -1) {
!     df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSzzz");
!     } else if (s.length()>19 && s.indexOf('.') == -1) {
!     df = new SimpleDateFormat("yyyy-MM-dd HH:MM:sszzz");
!     } else if (s.length()>19 && s.indexOf('.') != -1) {
!     df = new SimpleDateFormat("yyyy-MM-dd HH:MM:ss.SS");
!     } else if (s.length()>10 && s.length()<=18) {
!     df = new SimpleDateFormat("yyyy-MM-dd HH:MM:ss");
      } else {
!     df = new SimpleDateFormat("yyyy-MM-dd");
      }
!
      try {
      return new Timestamp(df.parse(s).getTime());
      } catch(ParseException e) {
--- 462,510 ----
      String s = getString(columnIndex);
      if(s==null)
      return null;
!
!     boolean subsecond;
!     //if string contains a '.' we have fractional seconds
!     if (s.indexOf('.') == -1) {
!       subsecond = false;
!     } else {
!       subsecond = true;
!     }
!
!     //here we are modifying the string from ISO format to a format java can understand
!     //java expects timezone info as 'GMT-08:00' instead of '-08' in postgres ISO format
!     //and java expects three digits if fractional seconds are present instead of two for postgres
!     //so this code strips off timezone info and adds on the GMT+/-...
!     //as well as adds a third digit for partial seconds if necessary
!     StringBuffer strBuf = new StringBuffer(s);
!     char sub = strBuf.charAt(strBuf.length()-3);
!     if (sub == '+' || sub == '-') {
!       strBuf.setLength(strBuf.length()-3);
!       if (subsecond)  {
!         strBuf = strBuf.append('0').append("GMT").append(s.substring(s.length()-3, s.length())).append(":00");
!       } else {
!         strBuf = strBuf.append("GMT").append(s.substring(s.length()-3, s.length())).append(":00");
!       }
!     } else if (subsecond) {
!       strBuf = strBuf.append('0');
!     }
!
!     s = strBuf.toString();
!
      SimpleDateFormat df = null;
!
!     if (s.length()>23 && subsecond) {
!       df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSzzzzzzzzz");
!     } else if (s.length()>23 && !subsecond) {
!       df = new SimpleDateFormat("yyyy-MM-dd HH:mm:sszzzzzzzzz");
!     } else if (s.length()>10 && subsecond) {
!       df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
!     } else if (s.length()>10 && !subsecond) {
!       df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
      } else {
!       df = new SimpleDateFormat("yyyy-MM-dd");
      }
!
      try {
      return new Timestamp(df.parse(s).getTime());
      } catch(ParseException e) {
*** interfaces/jdbc/org/postgresql/jdbc2/PreparedStatement.java.orig    Fri Jan 12 17:40:55 2001
--- interfaces/jdbc/org/postgresql/jdbc2/PreparedStatement.java    Sat Jan 13 15:31:45 2001
***************
*** 312,321 ****
       */
      public void setDate(int parameterIndex, java.sql.Date x) throws SQLException
      {
!       SimpleDateFormat df = new SimpleDateFormat("''yyyy-MM-dd''");
!
        set(parameterIndex, df.format(x));
!
        // The above is how the date should be handled.
        //
        // However, in JDK's prior to 1.1.6 (confirmed with the
--- 312,321 ----
       */
      public void setDate(int parameterIndex, java.sql.Date x) throws SQLException
      {
!           SimpleDateFormat df = new SimpleDateFormat("''yyyy-MM-dd''");
!
        set(parameterIndex, df.format(x));
!
        // The above is how the date should be handled.
        //
        // However, in JDK's prior to 1.1.6 (confirmed with the
***************
*** 350,357 ****
       * @exception SQLException if a database access error occurs
       */
      public void setTimestamp(int parameterIndex, Timestamp x) throws SQLException
!     {
!         set(parameterIndex, "'" + x.toString() + "'");
      }

      /**
--- 350,361 ----
       * @exception SQLException if a database access error occurs
       */
      public void setTimestamp(int parameterIndex, Timestamp x) throws SQLException
!         {
!           SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
!           df.setTimeZone(TimeZone.getTimeZone("GMT"));
!           StringBuffer strBuf = new StringBuffer("'");
!           strBuf.append(df.format(x)).append('.').append(x.getNanos()/10000000).append("+00'");
!       set(parameterIndex, strBuf.toString());
      }

      /**
*** interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java.orig    Fri Jan 12 16:47:28 2001
--- interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java    Sat Jan 13 15:16:14 2001
***************
*** 465,506 ****
      String s = getString(columnIndex);
      if(s==null)
      return null;
!
!     // This works, but it's commented out because Michael Stephenson's
!     // solution is better still:
!     //SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
! // Modification by Jan Thomae
!     String sub = s.substring(s.length() - 3, s.length()-2);
!     if (sub.equals("+") || sub.equals("-")) {
!             s = s.substring(0, s.length()-3) + "GMT"+ s.substring(s.length()-3, s.length())+":00";
      }
! // -------
!        // Michael Stephenson's solution:
      SimpleDateFormat df = null;

! // Modification by Jan Thomae
!     if (s.length()>27) {
!     df = new SimpleDateFormat("yyyy-MM-dd HH:mm:sszzzzzzzzz");
!     } else
! // -------
!     if (s.length()>21 && s.indexOf('.') != -1) {
!     df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSzzz");
!     } else if (s.length()>19 && s.indexOf('.') == -1) {
!     df = new SimpleDateFormat("yyyy-MM-dd HH:MM:sszzz");
!     } else if (s.length()>19 && s.indexOf('.') != -1) {
!     df = new SimpleDateFormat("yyyy-MM-dd HH:MM:ss.SS");
!     } else if (s.length()>10 && s.length()<=18) {
!     df = new SimpleDateFormat("yyyy-MM-dd HH:MM:ss");
      } else {
!     df = new SimpleDateFormat("yyyy-MM-dd");
      }
!
      try {
      return new Timestamp(df.parse(s).getTime());
      } catch(ParseException e) {
      throw new PSQLException("postgresql.res.badtimestamp",new Integer(e.getErrorOffset()),s);
      }
    }

    /**
     * A column value can be retrieved as a stream of ASCII characters
--- 465,520 ----
      String s = getString(columnIndex);
      if(s==null)
      return null;
!
!     boolean subsecond;
!     //if string contains a '.' we have fractional seconds
!     if (s.indexOf('.') == -1) {
!       subsecond = false;
!     } else {
!       subsecond = true;
!     }
!
!     //here we are modifying the string from ISO format to a format java can understand
!     //java expects timezone info as 'GMT-08:00' instead of '-08' in postgres ISO format
!     //and java expects three digits if fractional seconds are present instead of two for postgres
!     //so this code strips off timezone info and adds on the GMT+/-...
!     //as well as adds a third digit for partial seconds if necessary
!     StringBuffer strBuf = new StringBuffer(s);
!     char sub = strBuf.charAt(strBuf.length()-3);
!     if (sub == '+' || sub == '-') {
!       strBuf.setLength(strBuf.length()-3);
!       if (subsecond)  {
!         strBuf = strBuf.append('0').append("GMT").append(s.substring(s.length()-3, s.length())).append(":00");
!       } else {
!         strBuf = strBuf.append("GMT").append(s.substring(s.length()-3, s.length())).append(":00");
!       }
!     } else if (subsecond) {
!       strBuf = strBuf.append('0');
      }
!
!     s = strBuf.toString();
!
      SimpleDateFormat df = null;

!     if (s.length()>23 && subsecond) {
!       df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSzzzzzzzzz");
!     } else if (s.length()>23 && !subsecond) {
!       df = new SimpleDateFormat("yyyy-MM-dd HH:mm:sszzzzzzzzz");
!     } else if (s.length()>10 && subsecond) {
!       df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
!     } else if (s.length()>10 && !subsecond) {
!       df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
      } else {
!       df = new SimpleDateFormat("yyyy-MM-dd");
      }
!
      try {
      return new Timestamp(df.parse(s).getTime());
      } catch(ParseException e) {
      throw new PSQLException("postgresql.res.badtimestamp",new Integer(e.getErrorOffset()),s);
      }
    }
+

    /**
     * A column value can be retrieved as a stream of ASCII characters